No abstract

Migratory and local bees in Massachusetts were analyzed for seven viruses. Three were detected: black queen cell virus (BQCV), deformed wing virus (DWV), and sacbrood virus (SBV). DWV was most common, followed closely by BQCV and then by SBV. BQCV and SBV were present at significantly higher rates in the migratory bees assayed, bringing into question the impact that these bees have on the health of local bee populations.

No abstract

Larvae of cranberry tipworm, Dasineura oxycoccana Johnson, disrupt early season growth of cranberry (Vaccinium macrocarpon Aiton) uprights or shoots by feeding on apical meristem tissue. A 2-yr field study was carried out at three different locations to determine the impact of tipworm feeding injury on the reproductive and vegetative growth of two cranberry cultivars ('Howes' and 'Stevens') in Massachusetts. In addition to tipworm-injured and intact control uprights, an artificial injury treatment simulating tipworm feeding was also included. Individual uprights of cranberry exhibited tolerance to natural (tipworm) and simulated apical meristem injury in the current growing season (fruit production) and results were corroborated by a greenhouse study. In the field study, weight of fruit was higher in tipworm-injured uprights as compared with intact control uprights at the sites with Howes. However, majority of injured uprights (tipworm and simulated) did not produce new growth from lateral buds (side-shoots) before the onset of dormancy. In the next growing season, fewer injured uprights resumed growth and produced flowers as compared with intact uprights at two of the three sites. We suggest that multiple-year studies focusing on whole plant response to tipworm herbivory will be required to determine the costs of chronic feeding injury over time.

No abstract

A scanning electron microscopy study was carried out on the dermal pores, ducts and wax secretion in the mealybug Maconellicoccus hirsutus Green. The observations reveal that the hollow sticky filamentous wax plays an important role in forming the ovisac in adult females and cocoon in males. The sticky nature of the wax helps in attaching the ovisac to the substrate. Trilocular pores produce long curly filamentous wax covering the entire body of the mealybug. The multilocular disc pores produce short curly filaments in females and long ones in males. Different types of dermal pores and ducts produce specific types of wax which protect the insect from its predators and enemies. The wax filaments protect the eggs from desiccation and provide physical protection, and also avoid the eggs sticking together inside the ovisac. Moreover, adult males have several pleural pores on the posterolateral sides, differing structurally from other stages and producing filamentous wax.

No abstract

Mycoparasitic activities of various isolates of Trichoderma viride, T. harzianum, T. hamatum, T. longibrachiatum, T. koningii, T. pseudokoningii, Gliocladium virens and Laetisaria arvalis were studied against a serious plant pathogen, Botryodiplodia theobromae by scanning electron microscopy (SEM). Macroscopic observations of fungal growth in dual‐cultures revealed that most of the isolates made hyphal contact with the pathogen within 2 days after inoculation, leading to the inhibition in pathogen growth. However, T. viride Tv‐4, T. hamatum and T. pseudokoningii inhibited pathogen growth before hyphal contact and exhibited an inhibition zone between the colonies of both fungi. SEM investigations demonstrated that in case of hyphal interaction, the firm binding of antagonists (T. viride Tv‐1 & Tv‐3, T. harzianum Th‐1 & Th‐2, T. longibrachiatum and L. arvalis) to B. theobromae hyphae established either by coiling around its hyphae, or by penetrating its hyphal cells by forming hooks, haustoria and appressoria‐like structures which invariably led to cell disruption. Although T. koningii and G. virens Gv‐2 & Gv‐3 did not interact physically by way of coiling and penetration, they produced wall lytic enzymes or antifungal substances after coming in contact with B. theobromae which caused wrinkling, bursting and collapsing of pathogen mycelium. It is, therefore, suggested that the outcome of the interaction of antagonist and pathogen was most likely determined by initial hyphal contact that triggered a series of events in pathogen degradation.