Apis mellifera (Insecta: Hymenoptera) in the target of neonicotinoids: A one-way ticket? Bioinsecticides can be an alternative.

The recent decline of Apis mellifera populations around the world has been subject of intense research due to ecological and economic damages resulting from the loss of pollination services. The intensive use of insecticides from the neonicotinoids group is among the possible causal factors of this decline, including also sub-lethal effects. However, the use of synthetic insecticides has been increased on a global scale in the recent decades. In order to evaluate an alternative to the use of neonicotinoids, this work investigated the effects of a bioinsecticide and its major compound on A. mellifera (Apidae: Hymenoptera), one of the main pollinators of crop plants. For this, bees were exposed, by contact and ingestion, to the essential oil of Cymbopogon martinii (Poaceae: Poales), to geraniol (major compound) and the insecticide imidacloprid to evaluate the toxicity and behavioral effects as well as the locomotion changes and immune responses of bees treated with these compounds. In general, toxicity was greater through ingestion and the insecticide imidacloprid was more toxic to A. mellifera compared to the essential oil and its major compound. The individual and collective behaviors (i.e. trophallaxis, grooming, avoidance) as well as the immune responses of bees were not significantly affected by bioinsecticides. However, the locomotion response and flight orientation of the bees were significantly altered by insecticide when administered by ingestion. Our results highlight the potential of C. martinii essential oil and its major compound as a possible alternative to mitigate the harmful effects of neonicotinoids on bees.

Combined foraging strategies and soldier behaviour in Nasutitermes aff. coxipoensis (Blattodea: Termitoidea: Termitidae).

A range of behavioural strategies and sensory abilities allows animals to minimize costs involved in food search. By building a network of tunnels and presenting a large number of soldiers (i.e., trophically dependent individuals), Nasutitermes spp. termites feature behaviours that imply additional costs during this process. Here we evaluated N. aff. coxipoensis foraging strategies focusing on the role of soldiers during foraging. Field experiments were carried out via nests transplantation to dune areas, and laboratory experiments evaluated termite responses to sternal gland chemical signals from workers and soldiers. N. aff. coxipoensis presented primarily nocturnal foraging. Soldiers typically initiated foraging; however, in established trails, the number of workers was always higher than that of soldiers. The number of trails remained constant over time, while the number of tunnels increased linearly over time. A higher proportion of tunnels originated in surrounding areas than directly from the nests. At observation points with tunnels, there were more stationary than walking soldiers; the opposite was true at observation points without tunnels. In mixed groups, the workers chose to follow soldier chemical signals, and in these groups, soldiers were the first to follow trails. Our results allowed us to identify a not common foraging strategy in termite species; which included the establishment of trails followed by construction of tunnels. Such foraging strategies occur predominantly at night and soldiers play a key role in the foraging process. This foraging strategy reported here seems to be employed to optimize energetic gain.

Insetos indutores de galhas da porção sul da Cadeia do Espinhaço, Minas Gerais, Brasil / Gall inducing insects from southern portion of the Espinhaço Range, Minas Gerais, Brazil

A riqueza de insetos galhadores é maior nas latitudes intermediárias em hábitats quentes e com vegetação esclerófila sob estresse hídrico e de nutrientes. Em regiões tropicais, os campos rupestres são indicados como hábitats ricos em espécies de insetos galhadores. Neste trabalho, foram descritas as galhas induzidas por insetos e suas plantas hospedeiras na porção sul da Cadeia do Espinhaço, sudeste do Brasil. Foram selecionados 60 sítios em seis regiões ao longo na porção sul da Cadeia do Espinhaço no estado de Minas Gerais. Em cada sítio 100 plantas foram amostradas totalizando 6.000 plantas censuradas ao longo de um gradiente altitudinal de 668 a 1860m. Foram encontrados 241 morfotipos de galhas em 142 espécies de plantas distribuídas em 29 famílias e de um total de 384 espécies de plantas amostradas. As famílias mais ricas em espécies de insetos galhadores foram Asteraceae (42 por cento), principalmente espécies do gênero Baccharis. A maior parte das galhas (85 por cento) foi induzida por insetos da família Cecidomyiidae seguidos por Lepidoptera (4 por cento) e Homoptera (3 por cento). Os ramos foram os órgãos mais freqüentemente atacados (72 por cento) enquanto que os morfotipos mais comuns foram o elíptico (37 por cento) e o globóide (36 por cento). A espécie de planta hospedeira que apresentou mais morfotipos de galhas foi Baccharis pseudomyriocephala com 10 galhas distintas. Este estudo sustenta a afirmativa que campos rupestres apresentam uma elevada riqueza em espécies de insetos galhadores.

Galling species richness is higher at intermediate latitudes on warm habitats and sclerophyllous vegetation under water and nutrient stress. In the tropical region, galling species richness is higher in rupestrian fields. Here the gall-inducing insects and their host plants of the southern portion of the Espinhaço range, southeastern Brazil are described. 60 study sites from six distinct regions along the Espinhaço range, at Minas Gerais state were selected. In each study site 100 plants were sampled summing up to 6,000 plants censused along an altitudinal gradient ranging from 668m to 1860m a.s.l. A total of 241 distinct galls morphotypes were found on 142 host plant species belonging to 29 families from a total 384 species censused. The richest galling fauna was found in the Asteraceae (42 percent), mainly the genus Baccharis. The largest proportion of galls (85 percent) was induced by Cecidomyiidae followed by Lepidoptera (4 percent) and Homoptera (3 percent). Stems were the most frequently galled plant organ (72 percent) while the most common shapes were elliptical (37 percent) and globoid (36 percent). The host plant species presenting the highest number of gall morphotypes types was Baccharis pseudomyriocephala with 10 galls. This study supported the assertion that rupestrian fields present the highest galling species richness.

[Survival of the mite Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) under starvation]. / Sobrevivência do ácaro Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) na ausência de alimento.

The ability of a natural enemy to tolerate starvation increases its chances to survive in the absence of food, what is an important factor for its success in storage grain environment. The objective of the present work was to assess the survival of Acarophenax lacunatus (Cross & Krantz) in the absence of food. The experiment used individualized physogastric females of A. lacunatus placed in petri dishes (5 cm diameter) and maintained at 20, 25, 28, 30 and 32 degrees C, 50+/-5 % R.H. and 24h scotophase. The number of live mites was recorded every 6h thus assessing the progeny survival without food at different temperatures. The mites died within 60h at the temperatures 30 degrees C and 32 degrees C, while they survived for up to 108h at 20, 25 and 28 degrees C. The mean lethal time for death was 58.6h for the lowest temperatures and 39.3h for the highest temperatures. Thus, A. lacunatus subjected to starvation lived longer under lower temperatures, what is probably due to its lower metabolism. In contrast, the mites survived for about 90h at 28 degrees C, temperature commonly observed in tropical and subtropical climates, what may favor their use as control agents of stored product insects in these regions.

Sobrevivência do ácaro Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) na ausência de alimento / Survival of the mite Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) under starvation

A habilidade de um inimigo natural de suportar a inanição aumenta suas chances de sobrevivência na ausência de alimento, o que é um fator importante para seu sucesso em ambientes de armazenamento de grãos. O objetivo deste trabalho foi avaliar a sobrevivência de Acarophenax lacunatus (Cross & Krantz) na ausência de alimento. O experimento consistiu na utilização de fêmeas de A. lacunatus em processo de fisogastria, individualizadas em placas de Petri (5 cm diâmetro) e mantidas às temperaturas de 20, 25, 28, 30 e 32°C, 50 ± 5 por cento de U.R. e escotofase de 24h. O número de ácaros vivos foi contabilizado a cada 6h, avaliando-se assim, a sobrevivência da progênie de A. lacunatus sob regime de inanição, nas diferentes temperaturas. Nas temperaturas de 30°C e 32°C, os indivíduos de A. lacunatus morreram até 60h enquanto nas temperaturas de 20, 25 e 28°C a mortalidade ocorreu após 108h na ausência de alimento. O tempo médio para a morte dos indivíduos da progênie de A. lacunatus foi de 58,6h nas temperaturas abaixo de 28°C e de 39,3h para as temperaturas mais altas. Os ácaros submetidos à inanição tenderam a viver mais em temperaturas baixas, o que talvez seja explicado pela diminuição do seu metabolismo. Entretanto, A. lacunatus conseguiu sobreviver por cerca de 90h à temperatura de 28°C, a qual é comumente observada em regiões tropicais e subtropicais, o que pode favorecer sua utilização para o controle de insetos de produtos armazenados nessas regiões.

The ability of a natural enemy to tolerate starvation increases its chances to survive in the absence of food, what is an important factor for its success in storage grain environment. The objective of the present work was to assess the survival of Acarophenax lacunatus (Cross & Krantz) in the absence of food. The experiment used individualized physogastric females of A. lacunatus placed in petri dishes (5 cm diameter) and maintained at 20, 25, 28, 30 and 32°C, 50 ± 5 percent R.H. and 24h scotophase. The number of live mites was recorded every 6h thus assessing the progeny survival without food at different temperatures. The mites died within 60h at the temperatures 30°C and 32°C, while they survived for up to 108h at 20, 25 and 28°C. The mean lethal time for death was 58.6h for the lowest temperatures and 39.3h for the highest temperatures. Thus, A. lacunatus subjected to starvation lived longer under lower temperatures, what is probably due to its lower metabolism. In contrast, the mites survived for about 90h at 28°C, temperature commonly observed in tropical and subtropical climates, what may favor their use as control agents of stored product insects in these regions.

Diversity of bees and their floral resources at altitudinal areas in the Southern Espinhaço Range, Minas Gerais, Brazil

A porção sul da Cadeia do Espinhaço apresenta amplas áreas cobertas por campos altitudinais tropicais, quartizíticos ou metalíferos. Esses ecossistemas estão extremamente ameaçados, devido ao alto impacto antrópico, como a mineração e a urbanização. Nesse estudo inventariou-se a fauna e flora apícola durante um ano em uma área de campo rupestre (Serra de Ouro Branco) e durante dois anos em uma área de canga (Ouro Preto). Foram realizadas coletadas quinzenais de 8:00h às 17:00h. Foram coletados 677 indivíduos pertencentes a 91 espécies de abelhas de cinco famílias. Apidae foi a família mais rica e abundante, seguida por Halictidae e Megachilidae. As abelhas visitaram 46 espécies de plantas e as famílias mais visitadas foram: Asteraceae (n = 220), Malpighiaceae (n = 95), Melastomataceae (n = 94), Fabaceae (n = 78), e Solanaceae (n = 63). A região de Ouro Branco apresentou maior diversidade (H = 1,47) que Ouro Preto (H = 1,17). A baixa riqueza e abundância de abelhas, quando comparada a outras regiões de cerrado, podem ser atribuídas aos fatores ambientais das áreas de estudo: alta altitude, temperatura e disponibilidade de recursos florais. Áreas de canga e campo rupestre abrigam espécies raras e ameaçadas de extinção da fauna e flora. Áreas no sul do Espinhaço podem, entretanto, serem consideradas possíveis áreas de conservação biológica permanente.

Diversity of bees and their floral resources at altitudinal areas in the Southern Espinhaço Range, Minas Gerais, Brazil.

The Southern Espinhaço Range consists of large areas covered by quartzitic or metaliferous tropical altitudinal fields. The Espinhaço Range ecosystems are endangered by anthropic high impacts, particularly due to mining and urbanization. We conducted a one-year inventory of the bee flora and fauna at the quartzitic Ouro Branco Mountains and a two-year survey of the metaliferous Ouro Preto fields. The samples were collected twice a month, from 8:00 am to 5:00 pm. The bees (677) belonged to 91 species, five families. The family Apidae was the richest and most abundant, followed by the Halictidae and Megachilidae. The bees visited 46 flowering plant species; the most visited plants were the Asteraceae (n = 220), the Malpighiaceae (n = 95), the Melastomataceae (n = 94), the Fabaceae (n = 78), and the Solanaceae (n = 63). Diversity was higher in Ouro Branco (H = 1.47) than in Ouro Preto (H = 1.17). The low richness and abundance of bees in our research site when compared to other Brazilian "Cerrado" areas can be due to the high altitude, low temperature, and low availability of flowers we found. "Canga" and rupestrian areas house fauna and flora species that are rare and threatened by extinction. The southern Espinhaço areas can, therefore, be given the status of permanent biodiversity preservation area.