The phenology of Lygus rugulipennis, the European tarnished plant bug, on late-season strawberries, and control with insecticides

The phenology of Lygus rugulipennis, the European tarnished plant bug, was studied in fields of strawberries producing late-season (July to September) crops. Adults invaded fields in small numbers, mainly in July. Large numbers of nymphs were found in late July and early August; these matured into adults from late August. Adults formed the overwintering population; some remained in strawberry fields but left in spring to feed on other host plants. All the insecticides tested, i.e. malathion, chlorpyrifos, heptenophos, cypermethrin, bifenthrin and trichlorfon, gave good short-term control of nymphs.     

Relationships between the occurrence of misshapen fruit on late-season strawberry in the United Kingdom and infestation by insects, particularly the European tarnished plant bug, Lygus rugulipennis

In experiments in which the European tarnished plant bug, Lygus rugulipennis, was caged on the developing flowers or young fruits of strawberry, the insects caused malformation of the fruits. Another species of capsid, Plagiognathus chrysanthemi, caused similar damage; this species is less numerous than L. rugulipennis on late-season crops of strawberry in UK. Other insects which sometimes occur in large numbers in the flowers of late-season strawberry, i.e. various species of thrips and pollen beetles, did not cause fruit malformation in caging experiments, though thrips sometimes caused discoloration of the fruit. In field experiments where numbers of L. rugulipennis were reduced by the use of insecticides, the amount of misshapen fruit was reduced greatly compared to untreated plots. Correlations between the numbers of L. rugulipennis present at the early stages of fruit development and damage scores for fruit deformity were highly significant. This capsid is likely to be the major cause of fruit malformation in late-season crops of strawberry in the UK.     

Effects of mushroom size on the structure of a mycophagous arthropod community: Comparison between infracommunities with different types of resource utilization

The effects of the size of a patchy resource on the structure of a mycophagous arthropod community were examined by comparing numerical responses to the size of individual mushrooms between visitor and dweller communities. A total of 17 fungal genera in nine families were identified during the 13month survey period. A total of 35 arthropod families from nine orders were recorded, with the Hypogastruridae (Collembola) forming 97% of the number of individuals in the visitor community. The response of the visitor community (i.e. number of families, number of individuals, density per mushroom size and diversity) to mushroom size varied in each survey month according to hypogastrurid density. The response of the community composition to mushroom size also varied monthly with hypogastrurid density. In the dweller community, 12 families in three orders were recorded, and one coleopteran and five dipteran families accounted for 90% of the number of individuals. Although the density of dwellers in a mushroom varied between months, the response of the community properties to mushroom size was consistent throughout the survey period. Community composition varied monthly with mushroom size. These results suggest that the size of individual mushrooms is likely to have a greater effect on the structure of dweller communities than visitor communities. Thus, the characteristics of a patchy resource may exert different impacts on the structure of different arthropod communities utilizing the same resource, but in a different manner.