Toxicity, behavioural and biochemical effect of Piper betle L. essential oil and its constituents against housefly, Musca domestica L.

Housefly, Musca domestica L. is a pest of public health importance and is responsible for spreading diseases like typhoid, diarrhoea, plague etc. Indiscriminate reliance on synthetic insecticides has led to development of insecticide resistance and ill effect to humans and nontarget animals. This demands an alternative and safer pest control option. This study evaluates the biological effect of Piper betle L essential oil and its constituent eugenol, eugenol acetate, and ß - caryophyllene on the housefly. The major components present in P. betel EO were safrole (44.25%), eugenol (5.16%), ß -caryophyllene (5.98%), ß -selinene (5.93%), α-selinene (5.27%) and eugenol acetate (9.77%). Eugenol caused 4.5fold higher ovicidal activity (EC50 86.99 µg/ml) than P. betle EO (EC50 390.37 µg/ml). Eugenol caused fumigant toxicity to adults (LC50 88.38 mg/dm3). On contact toxicity by topical application, eugenol acetate, eugenol and ß-caryophyllene caused higher mortality to larval and adult stages than EO. FESEM (Field Emission Scanning Electron Microscope) images reveal that exposure to P. betle EO causes the shrinkage of the larval cuticle. Both EO and eugenol induced the detoxifying enzymes Carboxyl esterase (Car E) and Glutathione S - transferases (GST) in larvae and adults. EO and eugenol at 0.2% caused effective repellence and oviposition deterrence to M. domestica adults and this merits their use as alternative strategy to manage M. domestica.

First description of the male of Anagyrus almoriensis Shafee, Alam amp; Agarwal (Hymenoptera: Encyrtidae) with details of new host Pseudococcus calceolariae (Maskell) (Hemiptera: Pseudococcidae) on Rubus ellipticusnbsp;(Rosaceae) from Himalayas.

The male of Anagyrus almoriensis Shafee, Alam Agarwal (Hymenoptera: Encyrtidae) is described and illustrated from India along with notes on its associated hosts and types.

The cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Coccomorpha: Pseudococcidae) arrives in India.

Invasive species threaten the ecological and economic wellbeing of a country (Pimentel et al. 2001). In the last decade, several mealybugs and soft scale insects have been accidentally introduced to India, of which some have become serious pests (e.g., Phenacoccus solenopsis Tinsley, Paracoccus marginatus Williams Granara de Willink, Phenacoccus madeirensis Green and Pseudococcus jackbeardsleyi Gimpel Miller); others are widening their host ranges and spreading rapidly. Kilifia acuminata (Signoret) and Protopulvinaria longivalvata Green seem relatively harmless but Trijuba oculata (Brain) and Pulvinaria urbicola Cockerell cause economic damage (Joshi Rameshkumar 2013; Joshi 2017).

Two new species of Rhogadopsis Brèthes (Braconidae: Opiinae) as solitary parasitoids of Merochlorops species complex (Diptera: Chloropidae) from India.

During surveys for the potential biocontrol agents Merochlorops species complex (Diptera: Chloropidae), to control the invasive weed Hedychium gardnerianum Sheppard ex Ker Gawl. (Zingiberaceae), two new species of Rhogadopsis Brèthes (Braconidae: Opiinae) viz., R. gratia Gupta van Achterberg, sp. n. and R. macrusa Gupta van Achterberg, sp. n. were reared as solitary larval-pupal parasitoids of Merochlorops in the stems of H. gardnerianum. Interestingly, both wasp species have very different ovipositor lengths, in addition to other characters for species delimitation. Perhaps parasitism by the respective wasp species depends on the thickness of the stem harbouring the chloropid larvae. In the present study, both these new species of wasps are described and illustrated, together with notes on their biology. For the first time the genus Rhogadopsis has been found associated with Chloropidae; earlier records concern Agromyzidae.

Eri silkworm (Samia ricini), a non-mulberry host system for AcMNPV mediated expression of recombinant proteins.

The baculovirus expression system (BVES) based on Autographa californica nucleopolyhedrovirus (AcMNPV) is widely used for the expression of eukaryotic proteins. Several insect cells/larvae that are permissive to AcMNPV have been routinely used as hosts to express heterologous proteins. Domesticated Eri silkworm (Samia ricini), reared in many parts of India, Japan and China, is a non-mulberry silkworm. The present study shows that the Eri silkworm larvae are susceptible to intra-haemocoelical inoculation of AcMNPV. The virus replicates in the larva, as indicated by an increased viral loads in the haemolymph upon injection of a recombinant AcMNPV carrying green fluorescent protein gene. The virus showed localized replication in different tissues including the fat body, haemocytes, tracheal matrix and in the Malphigian tubules. The larval system was successfully used to express heterologous protein, by infecting with a recombinant AcMNPV carrying the 3ABC coding sequence of foot-and-mouth disease virus (FMDV). The study shows that the Eri silkworm larva can be a potential alternative bioreactor, for scaling up of the recombinant proteins employing the baculovirus system.