Wednesday, March 11, 2015

Black deer fly

The typical deer flies as today’s black deer fly (Chrysops niger) include about 100 species in North America alone. They are usually smaller than the horse flies, and they often have blotched wings and spotted eyes, which helps if you have to identify them.

Female deer flies are active during the day. These flies apparently are attracted to such things as movement, shiny surfaces, carbon dioxide, and warmth. Once on a host, they use their knife-like mouthparts to slice the skin and feed on the blood pool that is created. Bites can be very painful and especially cattle can be seriously affected by them. Numerous painful bites from large populations of these flies can reduce milk production from dairy cattle and interfere with grazing of cattle and horses because animals under attack will bunch together. Animals may even injure themselves as they run to escape these flies.

Friday, March 6, 2015

Glassy-winged sharpshooter

The glassy-winged sharpshooter (Homalodisca vitripennis) is a large leafhoppers. Adults are about 1.5 cm long and are generally dark brown to black when viewed from the top or side. The abdomen is whitish or yellow. The head is brown to black and covered with numerous ivory to yellowish spots.

This leafhopper species is native to southeastern North America. It has wreaked havoc on vineyards in California where it is introduced. It also occurs in unusually high numbers in citrus and avocado groves. The name sharpshooter comes from their habit of expelling excess watery waste with such force that it spurts a fair distance with an audible popping noise. 

Females lay their eggs on young leaves that have recently expanded. When it is first laid, the egg mass appears as a greenish blister on the leaf. The female covers the leaf blister with a secretion that resembles white chalk, making them easy to see. Shortly after egg hatch, the leaf tissue that contained the egg mass begins to turn brown leaving behind a permanent scar.

Thursday, March 5, 2015

Mining bee

Mining bees include about 1200 species in North America alone. They are solitary bees which means they don’t life in big colonies such as the honey bee but alone. Species like today’s Andrena spiraeana are springtime bees. Some even emerge before all snow has vanished. This might explain their little furry coat and which is very similar to the one bumble bees have.

Their nests are burrows in the soil, the entrance often hidden beneath a fallen leaf or other litter. Like any good homebuilder, the female waterproofs the walls of her brood cells using a secretion from a gland in her abdomen.

The individual species of mining bees are difficult to tell apart and in many cases they are best identified by looking at the flower species they pollinate as they seem to be very choosy when it comes to pollen.