The ultrastructure of nymphal dermal pores and the genitalia of adult male of Phenacoccus solenopsis (Hemiptera: Pseudococcidae).

The cotton mealybug, Phenacoccus solenopsis, has established itself as an invasive insect pest worldwide. It causes structural and physiological damage to various crops and can cause substantial financial losses in their production. The successful reproduction of this pest under a wide range of conditions is a key to its success. Despite this, the morphology of its genitalia, genital sensilla, and wax-producing dermal pores has received little attention, with little descriptions of their ultrastructure. By investigating those features with SEM, the present study revealed considerable new insights into the identification of the nymphal and adult stages of P. solenopsis. In addition, the description of the ultrastructural genital morphology of the immature stages of P. solenopsis has revealed characteristics that facilitate their discrimination. Trilocular pores were observed on both sides of the body, while the quinquelocular pores were distributed only on the ventral surface in both the first and second nymphal instars. The adult male is characterized by two pairs of waxy caudal filaments surrounded by clusters of 55 to 60 stellate pores, and each pregenital segment bears a pair of stellate pores composed of 4 or 5 peripheral loculi. Sensilla trichodea and numerous microtrichia are present on the pregenital segments. The penile sheath bears three subtypes of sensilla basiconica and also campaniformia, whereas the style bears three subtypes of sensilla campaniformia. The findings of this study could assist in the identification of the adult and nymphal stages of P. solenopsis, and also provide insights into the structures found on the genitalia of the adult male that possibly have an important role in mating events and copulatory behavior. Furthermore, these findings were able to contribute to better understanding the functional morphology of P. solenopsis.

A review: application of remote sensing as a promising strategy for insect pests and diseases management.

The present review provides a perspective angle on the historical and cutting-edge strategies of remote sensing techniques and its applications, especially for insect pest and plant disease management. Remote sensing depends on measuring, recording, and processing the electromagnetic radiation reflected and emitted from the ground target. Remote sensing applications depend on the spectral behavior of living organisms. Today, remote sensing is used as an effective tool for the detection, forecasting, and management of insect pests and plant diseases on different fruit orchards and crops. The main objectives of these applications were to collate data that help in decision-making for insect pest management and decreasing the environmental pollution of chemical pesticides. Airborne remote sensing has been a promising and useful tool for insect pest management and weed detection. Furthermore, remote sensing using satellite information proved to be a promising tool in forecasting and monitoring the distribution of locust species. It has also been used to help farmers in the early detection of mite infestation in cotton fields using multi-spectral systems, which depend on color changes in canopy semblance over time. Remote sensing can provide fast and accurate forecasting of targeted insect pests and subsequently minimizing pest damage and the management costs.

Insecticidal activity of some wild plant extracts against cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae).

The biological and phytochemical studies of four Egyptian wild plants/weed were studied against Spodoptera littoralis. M. senegalensis had highly significant antifeedant activity on the 3rd instar larvae of S. littoralis followed by Cl. amblyocarpa and S. argel, with 95.52, 45.23 and 32.12%, respectively. Larval mortality was relatively higher in case of M. senegalensis and S. argel. Extract of Cl. amblyocarpa was the only extract which causes malformation to pupae of S. littoralis. The highly pupal mortality was recorded in case of M. senegalensis extract (80%). The most effective extracts on reduction of pupal weight were Cl. amblyocarpa and A. setifera. The adult emergence percentage in case of M. senegalensis was 20% as compared to 95% in the control and all females moths resulting were deformed and all died before oviposition. The lowest number of eggs was observed in case of A. setifera extract and the eggs did not hatch. A. setifera and M. senegalensis possess both behavioural effects and post ingestive toxicity on the developmental stages of S. littoralis. A. setifera extract had the superior ovicidal activity on the viability of S. littoralis egg masses aged 72, 24 and 48 h, with 72.22, 39.77 and 31.82% reduction, respectively. The longer the post treatment period, the lower the bioefficacy of plant extracts against the target insect. M. senegalensis extract showed high latent mortality by the lapse of time, where 88% mortality occurred after 15 days from treatment at initial time and the residual effect remained for 5 days with 18% mortality after 15 days at 5 days post treatment. The lowest effective extract was S. argel which was effective for 3 days after treatment.