Effects of diet, temperature and photoperiod on development and survival of the bigeyed bug, Geocoris lubra

Bigeyed bugs (Geocoris spp., Hemiptera: Geocoridae) are common predators in Australian agricultural crops yet the development and reproductive biology of Australian geocorids has not been described before. Here we present the effects of diet, temperature and photoperiod on the development and survival of Geocoris lubra Kirkaldy from egg to adult. Nymphal survival of G. lubra reared on live aphids (Aphis gossypii Glover) was very low but improved slightly on a diet of Helicoverpa armigera (Hubner) eggs. Development was faster and nymphal survival improved significantly at 27 degrees C compared with 25 degrees C. Further investigation at 27 degrees C showed photoperiod influenced development time, but not survival of immature G. lubra. Development time was significantly longer at 10L:14D. Fecundity of first generation G. lubra was not affected by photoperiod, although egg viability was greater at 12L:12D

Sample Grain Influences the Functional Relationship Between Canopy Cover and Gopher Tortoise ( Gopherus polyphemus

Change in vegetation structure alters habitat suitability for the threatened gopher tortoise (Gopherus polyphemus). An understanding of this dynamic is crucial to inform habitat and tortoise management strategies. However, it is not known how the choice of the sample grain (i.e., cell size) at which vegetation structure is measured impacts estimates of tortoise-habitat relationships. We used lidar remote sensing to estimate canopy cover around 1573 gopher tortoise burrows at incrementally larger sample grains (1-707 m2) in 450 ha of longleaf pine (Pinus palustris) savanna. Using an information theoretic approach, we demonstrate that the choice of grain size profoundly influences modeled relationships between canopy cover and burrow abandonment. At the most supported grain size (314 m2), the probability of burrow abandonment increased by 1.7% with each percent increase in canopy cover. Ultimately, detecting the appropriate sample grain can lead to more effective development of functional relationships and improve predictive models to manage gopher tortoise habitats