Update on heat, April 7, 2005:

Even if we did not have instrument data to prove it, we would know that above-average heat was available for grasshopper growth in the late summer of 2003, because of the existence of a natural heat integrator. A grasshopper named Arphia conspersa is one of several species with a red wing. This species is fairly common in the early spring. It overwinters as an immature (hopper), and completes development when warm days begin in the spring. In springs following years with warm weather in the late summer, this hopper matures early and are seen flying with red wings, typically on the south-facing slopes of pastures, parks and grassland. I have noted maturity dates almost every spring. This year, this species suddenly appeared, fully developed (100% were adult) on March 28-29. This was confirmed April 6 and following. This early maturity date indicates that they are one to three weeks earlier than other years. Although this grasshopper is not a pest, it serves as an indicator and tells us that 2003 was relatively warm from a grasshopper's perspective, and that hatching could be early (late May). Although there is very limited information on pest grasshopper egg condition, an early and concentrated hatch seems to be likely, judging from this point. One thing that may reduce the problem is that the rates of egg-laying in 2003 were observed to be less than optimal and not as intense as in some recent years. This could be a slight mitigating factor, despite the large numbers of grasshoppers in many locations in August, 2003. We faced this condition in about 1987, when I entitled the forecast "High numbers but low reproduction". However, this factor will not prevent extensive hatching of hopper this year, when warm weather allows it.

- DJ