2013, Pol, Chanthy, Martin, Robert, Gunning, Robin V, Andrew, Nigel R

This is the first assessment of insect assemblages on soybean crops in Cambodia. Sweep netting and beat sheeting collection methods were used to evaluate the effectiveness of sampling arthropods and their collection efficiency in soybean crops and to determine soybean insect diversity and composition at two sites. Overall, arthropod populations sampled by sweep netting were substantially different compared to populations collected by beat sheeting. The sweep netting caught significantly higher numbers of most Orders; however, the beat sheeting caught a significantly higher number of Acari. Beat sheeting was also effective for sampling 'Nezara viridula' which is a major invertebrate pest of soybean. There was a significant interaction between location and collection methods for both Hemiptera and Hymenoptera assemblages. Selection of insect sampling method depends on many factors such as plant type, plant structure, field conditions, ease of use, cost of use and target insect species. However, the sweep netting was best for fast flying insects such as hymenopteran wasps and those located in upper parts of the plant canopy. The use of different sampling methods to assess pest, predator/parasitoid and general community structure in crops is crucial for assessing Integrated Pest Management strategies.

2015, Chanthy, Pol, Martin, Robert, Gunning, Robin V, Andrew, Nigel R

Laboratory studies were conducted to assess impacts of temperature and humidity regimes on the development of Nezara viridula (L.) (Hemiptera: Pentatomidae) from inland and coastal populations in NSW, Australia. Four temperature regimes, 25±2ºC, 30±2ºC, 33±2ºC, and 36±2ºC and two humidity regimes, 40±10% and 80±10% RH were applied in the experiment with a constant photoperiod of 14:10 h (L:D). The developmental time of the nymphal stage of N. viridula significantly decreased with increasing temperature. Percentage nymphal survival significantly decreased with increasing temperature or high humidity (80% RH) regimes. Longevity of N. viridula adults declined with increasing temperature or high humidity regimes and female longevity was longer than males. High temperatures (30, 33 and 36ºC) or high humidity significantly reduced reproductive performance and capacity of N. viridula compared to low temperature (25ºC) or low humidity (40% RH). However, high humidity significantly increased egg hatchability of N. viridula compared with a low humidity regime. Interactions of temperature and humidity regimes significantly changed incubation period, adult longevity, mating frequency, pre-mating period, egg-mass size and egg hatchability of N. viridula. Interactions of population location (coastal or inland), temperature and humidity regimes significantly changed incubation period and pre-oviposition period of N. viridula. Temperature and humidity are important environmental factors for the development and reproduction of N. viridula. Higher temperatures shorten the length of nymphal duration, but reduce nymphal survival. The optimum temperature for the development and reproduction of N. viridula was 25ºC with 40 ± 10% RH. No differences in nymphal duration, nymphal survival, adult longevity or reproduction performance between inland and coastal N. viridula populations were found under different climate conditions. We show the importance of assessing all life-stages in the response to varying temperature and humidity regimes, especially in terms of assessing responses to climate change.