The Bagrada bug is a new invasive pest that was found damaging cole crops in the fall of 2009. Native to the old world (Africa, India), the small stink bug was first reported in the U.S. from Orange county, CA in 2008. By August of 2009, the bug was found in Yuma, AZ, and in the Imperial, Coachella and Palo Verde Valleys of CA. Being a new pest, there is much we don't know about its biology and ecology in desert cropping systems. However, based on observation from this past produce season, we know that it can cause significant damage to seedling and transplanted cole crops, but is easy to kill with conventional insecticides. This presentation provides information on the biology and management of bagrada bugs on desert cole crops, based primarily on local observations and research, and to a lesser extent, published information obtained from Africa and India. This information was presented by John Palumbo at the Southwest Ag Summit on March 11, 2010.
To contact John Palumbo go to: jpalumbo@ag.arizona.edu

Viruses vectored by insects 
 
We are on the final section of virus transmission. Virus transmission by insects is one of the most efficient and economically important transmission in agriculture. When you have insects in your crops, not only you are losing your crops because of feeding/chewing by insects, a lot of insects also act as a vector of plant viruses. 
 
Seven out of 29 orders of insect feeding on living green land plants are vectors of plant viruses. 
Insect transmit viruses in 4 distinct modes: 
 

1. Non persistent transmission: The insects can acquire the virus in a matter if seconds/minutes and they are immediately viruliferous. The virus in retained in the stylet of the insect and are transmitted to the next plant the insect feeds on. The virus is retained in the vector only for few minutes and is lost after insect molting. Most viruses transmitted by aphids are non persistent. So when you see few aphids in your melon field and see cucumber mosaic virus symptoms 1-2 weeks later in your field, don’t be surprised. Aphids are efficient vectors, and since viruses are systemic it takes anywhere from few days to 2-3 weeks for the plants to show symptoms. Thus it is very important to manage insects in the field even if you don’t think the ‘pressure’ is not as high. 

Viruses transmitted in non-persistent manner:
 Papaya ringspot virus 
Zucchini yellow mosaic virus 
Watermelon mosaic virus

1. Semi-persistent transmission: The insects can acquire the virus in minutes/hours and there is no latent (incubation) period in the insect. The virus can stay in the insects foregut for hours and is lost after insect molting. Some species of aphids and whiteflies fall in this category.  Example: Cucurbit yellow stunting disorder virus in melons transmitted by whiteflies. 

1. Persistent circulative: Insects have to feed on virus infected plants for hours/days to acquire the virus and the virus has to incubate for hours/days in the insect. After insect can transmit the virus for weeks. Virus can be present in the vectors hemolymph but there is no multiplication of virus in the insect body. Vectors in this transmission includes: Aphids, leafhopper, whiteflies, treehopper. 

Example: Beet curly top virus transmission by beet leafhopper 
 

1. Persistent propagative:  Insects have to feed on virus infected plants for hours/days to acquire the virus and the virus has to incubate for hours/days in the insect. After insect can transmit the virus throughout its lifespan. The virus can multiply in the vector system and often times the virus particles are also passed on to the insect offspring. Tomato spotted wilt virus is transmitted on persistent propagative manner by 9 different species on thrips. 

 

Save the Date : 2024 Plant Pathology Workshop 
When: August 29^th 8AM-12 PM ( breakfast and Lunch provided by Gowan Company and BASF) 
Where: Yuma Ag Center, 6425 W 8^th Street 
What will covered: Plant Pathology program Updates, past season field trial results (we
have some exciting results to share), Q&A to help better Plant pathology program,
Industry panel discussion for all your industry related questions! See you in few weeks! 

In November the EPA announced new requirements for handling Paraquat (Gramoxone, Cyclone, Helmquat, Parazone, Firestorm). Paraquat was first registered in 1959 by ICI Ltd. It is used on more than 100 crops in more than 100 countries but is the most toxic herbicide that has been used for many years. The new regulations involve labelling, applicator certifications and the use of closed system packaging. New containers are required to include supplemental warnings and stickers attached to the containers that state “one sip can kill.” Retailers can continue to sell old labeled products until supplies are exhausted. Paraquat has been a restricted use pesticide, meaning that applicators have had to be licensed and certified to apply it, but new additional regulations now apply. Two certifications are now required and anyone handling the product needs to be certified. Working under the supervision of someone who is certified does not count. In addition to a Pesticide applicators license, handlers now have to have a paraquat specific training certificate. This can be obtained by on-line training at www.usparaquattraining.com. This has been developed by the National Pesticide Safety Education Center (NPSEC).

Area wide Insect Trapping Network   VegIPM Update, Vol. 12, No. 15, Jul 28,  2021
Results of pheromone and sticky trap catches can be viewed here.
 
Corn earworm:            
CEW moth counts decreased significantly since mid-June comparable to what we observed last summer.
 
Beet armyworm:         
Trap counts remain low in most locations  and are trending similar to last summer.
 
Cabbage looper:         
Cabbage looper numbers remain low consistent with the lack of activity this fall and summer compared to last season.
 
Whitefly:                     
Adult movement continuing to increase rapidly, particularly in Wellton and Dome Valley consistent with the termination of spring melons.
 
Thrips:                          
Thrips adult movement continuing to decline to numbers comparable to this time last year.
 
Aphids:                        
Aphid movement has been absent for the past 2 months typical with high summer temperatures.  
 
Leafminers:                 
Adult activity slightly above for mid-summer.
 
Diamondback moth:    
DBM trap counts have been zeroed out in all trap locations for all of July consistent with trends observed over the past 5 years.