No. 5/June 18, 2019

Degree days June 18
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the links below with the degree day accumulations above to determine what insect pests could be active in their area.

Buffalo Gnats
Insects can swarm for a variety of reasons. Bees swarm when they are preparing to leave their hive and establish a new one, locusts swarm when food becomes scarce and they need to relocate to feed, lovebugs swarm to find a mate efficiently and, for insects like buffalo gnats (also called black flies, Simuliidae), sometimes the local conditions are just right to support a larger than usual population. This year, Illinois has had cool, rainy conditions which are beneficial for buffalo gnats. Flooding and sustained high water levels may provide additional resources and reproductive habitat for the flies. Waterway restoration efforts can also create cleaner, healthier, aquatic ecosystem which benefit all aquatic animals, including buffalo gnats.

Hover Flies
Hover flies (aka syrphid flies or flower flies) are covering any nectar-producing flower in the garden this spring. These flies, commonly mistaken for bees, are one of our most prolific pollinators and aphid eaters in the Illinois garden but care must be taken to protect them when spraying pesticides.

Wild Parsnip
Wild parsnip (Pastinaca sativa) has been in the news recently, but many still do not know about this plant and the harm it can cause. It seems to be quite common now in central Illinois, so many have likely seen this plant before. Familiarity can breed complacency, unfortunately. The roadsides along I-72 between Springfield and Champaign were a full of it last week during a drive. Yet, ironically, that same day a reporter in Chicago was trying to contact me about the recent discovery of this weed there where it is much less common than in rural areas. The Chicago Tribune had run a story on it the day before. A few days before that, I identified a plant as being wild parsnip for the University of Illinois Plant Clinic. Who knew that the same inquiry would send the media’s gears into motion? And mine as well as the case may be…

Peach Leaf Curl
Peach leaf curl has been a common concern reported by many Extension offices this spring. Peach leaf curl is a fungal disease caused by Taphrina deformans and is one of the most commonly encountered diseases of peaches and nectarines, especially in home plantings. It primarily affects the foliage, but may also affect blossoms, young twigs, and fruit.

Record Keeping
Record keeping is an essential component of an integrated pest management plan. Records may include details on pest movement, site conditions, and successes or failures of treatments. These records allow applicators to determine which sites are more prone to pest issues and be able to track effective treatment options. While essential to successful pest management, there are also legal reasons to maintain records, especially when applying Restricted Use Pesticides (RUPs). There are specific types of information that you are required to maintain when using pesticides. Even though not necessary for all restricted use pesticides (RUP), wind direction and wind speed can be useful information.